1. Field of Invention
This invention relates a circuit breaker device for temporarily interrupting a circuit current, for example, when performing a maintenance service (such as inspection and maintenance) of an electric car, a hybrid car or the like having a high-voltage circuit for driving a motor.
2. Related Art
A conventional circuit breaker device for an electric car or the like comprises a plug box, having circuit terminals connected to open ends of an electric circuit through respective bus bars, and a plug body having short-circuit terminals fitted in and short-circuited to the respective circuit terminals of the plug box to thereby close the electric circuit.
The plug box comprises a box body having an open top (opening), and a box cover fixed to the box body to close the opening in the box body. Referring to FIG. 11, a plurality of (four in FIG. 11) bus bars 51 and 52 each in the form of a flat plate are fixedly mounted on the box body 50 in such a manner that those end portions 51a and 52a of the bus bars 51 and 52 to be connected to the open ends of the electric circuit project a predetermined amount from the box body 50.
The above conventional circuit breaker device has a problem that the pair of bus bars 51 (at the right side in FIG. 11), arranged on a straight line, can not be sufficiently insulated from the pair of bus bars 52 (at the left side in FIG. 11) arranged on a straight line.
Another problem is that heat is generated in the box body 50 by a circuit current in the electric circuit (high-voltage circuit) and other factor.